Modern mobile communication technology tends to provide users multimedia service of high-rate transmission. FIG. 1 is a schematic diagram illustrating the structure of a System Architecture Evolution (SAE). In FIG. 1, UE 101 is a terminal device for receiving data. Evolved Universal Terrestrial Radio Access Network (E-UTRAN) 102 is a radio access device, which includes an eNB/NodeB providing a wireless network interface for the UE. Mobility Management Entity (MME) 103 is configured to manage mobile context, session context and security information of the UE. Serving Gateway (SGW) 104 is configured to provide functions of a subscriber plane. MME 103 and SGW 104 can be located in the same physical entity. Packet Data Network Gateway (PGW) 105 is configured to implement charging and legal monitoring functions. PGW 105 and SGW 104 can be located in the same physical entity. Policy and Charging Rules Function Entity (PCRF) 106 is configured to provide Quality of Service (QoS) policies and charging rules. Serving General Packet Radio Service (GPRS) Support Node (SGSN) 108 is a network node device for providing routing for data transmission in a Universal Mobile Telecommunications System (UMTS). Home Subscriber Server (HSS) 109 is a home subsystem of the UE and is configured to protect user information including the current location of the UE, address of a service node, user security information, packet data context of the UE, and so on.
In current Long Term Evolution (LTE) system, each cell supports a maximum bandwidth of 20 MHz. In order to improve the peak rate of a UE, a Carrier Aggregation (CA) technology is introduced in a LTE-advanced system. With the Carrier Aggregation, the UE can simultaneously communicate with cells controlled by the same eNB and work on different carrier frequencies, thus the transmission bandwidth can be up to 100 MHz, the uplink and downlink peak rate of the UE can be multiplied.
In order to increase the transmission bandwidth, one user can be served by multiple cells, and the multiple cells can be covered by one eNB or multiple eNBs, the technique is referred to as Carrier Aggregation. FIG. 2 is a schematic diagram illustrating inter-eNB Carrier Aggregation. For a UE working in the case of the Carrier Aggregation, aggregated cells include a Primary Cell (PCell) and a Secondary Cell (SCell). PCell can be referred to as Serving Cell in the present application. There is only one PCell, and the PCell is always in an active state. The PCell can be handed over only through a handover process. The UE sends and receives Non-Access Stratum (NAS) information only in the PCell, and a Physical Uplink Control CHannel (PUCCH) can be sent only in the PCell.
According to different quality requirements, UE services can include a Guaranteed Bit Rate (GBR) service and a non-GBR service. For the GBR service, a certain transmission rate needs to be guaranteed. For non-GBR services of a user, an AMBR is defined, and the AMBR belongs to subscription information of the UE. Total rate of all non-GBR services cannot be greater than rate defined by AMBR. AMBR of a UE (UE-AMBR) set by the MME is set according to the subscription information of the UE, and cannot be greater than the AMBR value in the subscription information of the UE. There are UE-AMBR corresponding to uplink data and UE-AMBR corresponding to downlink data respectively. The MME sends a UE-AMBR to an eNB. The eNB has an uplink and a downlink scheduling function, with which, total rate of non-GBR services sent synchronously are not larger than the UE-AMBR. For example, suppose the uplink UE-AMBR is 10, and if there is data of two non-GBR services to be sent at certain moment, the rate of each non-GBR service schedulable by the eNB can be 5, if there is data of only one non-GBR service to be sent, the rate of the non-GBR service schedulable by the eNB can be 10.
The UE-AMBR is sent to the eNB by the MME when the UE enters the connection mode, and the MME establishes UE context at the eNB. The specific method includes: the MME sends the UE-AMBR carried in an “initial context set up request” message to the eNB; the eNB stories the UE-AMBR and uses the UE-AMBR in subsequent data scheduling. The current problem is as follows. When cells participating in Carrier Aggregation are covered by different eNBs (cells participating in Carrier Aggregation are controlled by different eNBs), multiple S1 bearers are established for the user between the SGW and the eNBs, non-GBR services of the UE can be established on different eNBs. Thus, current UE-AMBR cannot be applied to the case that one UE has multiple S1 bearers.